Improved method of forming designs upon metals, ivoey



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THOMAS SKINNER, O F PITTSBURG, PEN NS YQLVANIA.

Letters Patent No. 72,553, dated December 24, 186i.v

IMPRQVED METHOD, OF FORMING DESIGNS UPON METALS, IVORY, ea.

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Be it known that I, THOMAS SKINNER, of Pittsburg, in the county of Allegheny, and State of Pennsylvania, have invented a new and improved Method of Etching Pictorial Representations, Figures, Characters, Letters, or other Devices, upon Metals, Ivory, or similar substances; and I hereby declare that'the-following is afull, clear, and exact description of my invention, suffi'ciently plain to enable one skilled in the art to put it into practical operation. i

To produce plain or ornamental figures upon steel or other hard metal, I first engrave the design intended, to be represented upon a copper plate. I then make a kindof oily ink, by-boilingoil to a proper consistency, and stifl'en it by the addition of a small quantity of lamp-black, or other soft coloring-matter. This I rub intof the lines of the engraving on the copper plate, taking care, however,'to wipe the surface of the plate perfectly clean. On this plate, so prepared, I lay a sheet of thin paper, and submit them to the action of a powerful press, which causes-the paper to take up the oily ink from the lines of the engraving. I then take the print,

so obtained, and, while the oily ink is moist, lay it face or inky side down on the article to be ornamen ted,and

rub it slightly on the back to makethe transfer of the ink to the article complete. The paper .is then to be softened with water, and removed, leaving the ink on the steel, which, as soon asdone, is to be coveredwith a light spirit-varnish. This, when dry, is to be rubbed over with the oil of turpentine, or other solvent that will soften and remove the oily ink, leaving the surrounding parts protected by thevarnish. ,I then apply dilute acid to the exposed parts, previously covered by the ink, until the design is bitten sufiiciently deep, when the article acted upon is to be washed in water, to neutralize the acid. The spirit-varnish is now removed by the application of wood-naphtha, benzine, or other solv'en ts,'and the work will be found nearly equal to that on the copper plate, and far superior to that produced by any other manner of etching. I

For marking ivory, I proceed as in the caseof steel, above described, with this exception, that, after the work or'design is bitten in, and before the varnish is removed, I apply common writing-ink, or other dye that will leave a permanent stain in the lines or places acted upon by the acid, when the varnish is to be removed, in the manner hereinbefore stated. I

Another branch of this process I denominate frost-etchiug,"-which is efi'ected, in the following manner After the paper is removed from the article to be ornamented, I dust the ink remaining thereon with powdered resinous gum, which sticks to the oily inky transfer in small particles. The surplus being removed, those small 1 particles unite with the ink, and form a varnish in spots sufficiently strong to resist the actionof the acid in those places or points. When this is done, the work can be bitten out in the manner hereinbefore described, and the varnish removed, when the design or picture can be rubbed over with crocus,-chalk, or other substance, and the work is complete, showing a white ground and bright ornament.

Having thus stated the nature of my invention, I.wish it distinctly understood that I lay no claim to etching devices upon metals, ivory, and the like; but

What I do claim-is The herein-described method of preparing the design upon the article to be operated on, preparatory to the etching-process, by the means of transfers, substantially as set forth.

- THOMAS SKINNER.

Witnesses.

JOSIAH W. ELLS, JouN McKnNnA. 

